Means for making annular bodies of plastic material.



V J. H. PEARSON. v

MEANS FOR MAKING ANNULARBODIES 0F PLASTIC MATERIAL. APPLICATION FILED AUG-7,1912.

1 l 9 6, 74;. Patented Sept. 5, 1916.

IVITNESSES: [NI 221v TOR.

- h HQIWX PQQY I I n I BY m ATTORNEY.

JOHN HARVEY PnA'BsON, or INDIANAPOLIS, INDIANA, 'ASSIGNOR T onnrincn mrocaymr s COMPANY, 01 INDIANAPOLIS, INDIANA. n CORPORATION.

MEAN-S non MAKING imam: comes on rLAsrIeMATEnIaL.

Specification of Letters Patent. Patented Se t 5 1915.

Application filed August 7, 1912'. Serial No. 713,813.

To all whom it may concern:

Be it'known that I,JOHN HARVEY PEAR- soN, a citizen of the' United States, and a resident of Indianapolis, county of Marion,

'5 and State of Indiana, have'invented a certain useful Means for Making Annular Bodies of Plastic Material; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings.

The object of this invention is to provide means for the satisfactory and efiicient formation ofpolishingbuttons or. tools for making lenses and'kindred uses. In the manufacture of lens polishing buttbnsor tools it is used for compressinga plastic'material in annular form upon' a metal or solid base or holder. Thenietal base or holder is used for holding the polishing tool during its operation and the plastic material, which is solidified by the'compression, forms a highly desirable and successful polishing surface or means. Heretofore, difliculty hasbeen had 7 in forming or making a polishing buttqn .or tool from such plastic materialbecause of the difliculty of compressing it and forming.

it annula 'lyand upon the metal base, so as to render the tool suiiiciently-econoiuicalin construction, andywhat is 'of imore impor- 80 tance, suificientlyefiicient in operation.

The nature of the invention will be understood from the accompanying drawings and v the following description and claims.

In the drawings, Figure l is a central vertical section through the device with the press plunger and the table support partially broken away. Fig. 2 shows a central Vertical section of the lower part of thedevice above the table and partially broken away, with 40 the plastic material put in place to be compressed. Fig. 3 shows the same parts as Fig. 2 at the end of the pressing operation.

The object of the invention is to compress a polishing'body 10 to solidify it satisfactorily and make it hard and dense enough and give it shape and also cause it to adhere effectively to a metal base plate 11, sotha when the operation is finished said parts 10 and 11 will constitute together a polishing tool for polishing lenses and the like.

The metal base 11 is used for holding the .tool onto means for operating it and the polishing body 10 has an annular rib 12 which,

during thexoperation, is brought into cone tact with the lens for polishing it. This polishing body is made out of a suitable plastic material including rouge, such as lens grinders use, bound together bytar or other suitable material so as to make a comparatively hard and durable polishing body. Since only the annular rib 12 engages and polishes the lens it is desirable that the polishing body 10 be also annular and that there be holes 13 through thecentral portion of the metal base 11 for the passage of the water during the polishing operation.

The base 11 has in its upper surface an annular recess or cavity in which the body 10 is placed so that after the compression of the body 10 and its pressure upon the base 11, the two will be caused to adhere permanently together. The upper surface of the base plate 11 has a central recess surrounded by a vertical rib 14, which has the same diameter as the opening desired through the polishing body 10 and said recess extends for about half of the thickness of the plate 11, asshownqf- There is a stationary table or-bench 15 shown, above which a plate 16 lies and it has 0 holes in its upper surface to receive pins 17 from the base 11. In operation the plastic ing then soft and plastic. It is arranged on p the base 11 in crude form and in the annular recess in the base 11. Then the base 11 is laid in place upo'n the plate 16 and an annular casino- 18 put in place around the base 11 and polishing body, as shown in I*ig. -2, said casing being separable from the plate 16. a

After the foregoing the compressing means is operated. This consists of an outer cylindrical die 20 with the lower end 'of said .die fitting snugly and operating in the casing 18 and with the lower end formed so as to give the desired conformation to the upper surface of the polishing body 10. The outer die 20 is closed: at its upper end and has two Vertical slots about midway for the ends of a pin 24: which extends through the inner die 22 and limits the downward movement of said inner die relatively to the outer die. The inner die is of the same diameter as the recess in the base 11 so that when said inner die descends, it u ill enter said recess and give proper form and size to the central opening of the finished polishing tool. For

that purpose the inner'die is recessed somewhat at its lower end and as it descends, it removes the superfluous inner portion of the polishing body and forces it down through the openings 13 or out of the Way. The inner die is forced down by a spring 23, while the outer die is being actuated by the press plunger 21 above. This press plunger is actuated by suitable means, not shot/matter the other parts are in position. As the outer die goes down, the inner die will move at the same speed until it reaches the bot tom of the recess in the base 11. Then the inner die will stop its downward movement, while the outer die will move down as far as the material of the polishing body will permit. Then the degree of solidity or hardness can be determined more or less by the degree of compression brought about by the action of the outer die. The exact vertical thickness of the polishing bodyis not very material, as such tools can be used effectively whether of exactly the same thickness or not.

I claim as my invention: A

1. Means for forming annular bodies of plastic-material including a chamber, a bottom plate, a tubular casing thereon forming a chamber in which the plastic material is placed, a central die in said chamber and adapted to be forced through the plastic material, a-tubu-lar die surrounding said central die for compressing the material, and yielding means between said dies, whereby actuation of thetubular the will cause the simultaneous movement of the central die until it is stopped and after which said tubular die may be further moved to coiiopress the material.

2. Means for forming annular bodies of plastic material which consists in a bottom plate and easing Withinwhich said plastic material is located, a tubular die for shapmg one surface of the plastic material, means for actuating said tubular die, said tubular die having vertical slots in it, a die within saidtubular die for forming acen tral opening in said body of plastic material, a pin extending laterally 'from said inner die into said slots, and a. spring located between the inner and tubular dies arranged so that the actuation of the tubular die will cause the spring to actuate the inner die 3. Means for forming annular bodies of plastic material. including a chamber, a base plastic material including a chamber, a base for the plastic material having an annular recess for receiving material to be treated and a central recess, a central die adapted to move into said central recess, a tubular die surrounding said central die for compressing the material, and a spring between said central die and tubular die, said dies being arranged so that when the tubular die is actuated, the central die W llbe moved to its limit and thereafter the tubular die can,

move independently of the central die until the compression is completed.

In witness whereof, I have hereunto afiixed my signature in the presence of the Witnesses herein named,

JOHN HARVEY PEARSGNQ Witnesses:

J. H. W'nmis, E. H. Marc. 

